builtin: move C. calls to .c.v files (#11164)

vlib/builtin/map.c.v

@@ -0,0 +1,79 @@
+module builtin
+
+fn C.wyhash(&byte, u64, u64, &u64) u64
+
+fn C.wyhash64(u64, u64) u64
+
+// fast_string_eq is intended to be fast when
+// the strings are very likely to be equal
+// TODO: add branch prediction hints
+[inline]
+fn fast_string_eq(a string, b string) bool {
+	if a.len != b.len {
+		return false
+	}
+	unsafe {
+		return C.memcmp(a.str, b.str, b.len) == 0
+	}
+}
+
+fn map_hash_string(pkey voidptr) u64 {
+	key := *unsafe { &string(pkey) }
+	return C.wyhash(key.str, u64(key.len), 0, &u64(C._wyp))
+}
+
+fn map_hash_int_1(pkey voidptr) u64 {
+	return C.wyhash64(*unsafe { &byte(pkey) }, 0)
+}
+
+fn map_hash_int_2(pkey voidptr) u64 {
+	return C.wyhash64(*unsafe { &u16(pkey) }, 0)
+}
+
+fn map_hash_int_4(pkey voidptr) u64 {
+	return C.wyhash64(*unsafe { &u32(pkey) }, 0)
+}
+
+fn map_hash_int_8(pkey voidptr) u64 {
+	return C.wyhash64(*unsafe { &u64(pkey) }, 0)
+}
+
+// Move all zeros to the end of the array and resize array
+fn (mut d DenseArray) zeros_to_end() {
+	// TODO alloca?
+	mut tmp_value := unsafe { malloc(d.value_bytes) }
+	mut tmp_key := unsafe { malloc(d.key_bytes) }
+	mut count := 0
+	for i in 0 .. d.len {
+		if d.has_index(i) {
+			// swap (TODO: optimize)
+			unsafe {
+				if count != i {
+					// Swap keys
+					C.memcpy(tmp_key, d.key(count), d.key_bytes)
+					C.memcpy(d.key(count), d.key(i), d.key_bytes)
+					C.memcpy(d.key(i), tmp_key, d.key_bytes)
+					// Swap values
+					C.memcpy(tmp_value, d.value(count), d.value_bytes)
+					C.memcpy(d.value(count), d.value(i), d.value_bytes)
+					C.memcpy(d.value(i), tmp_value, d.value_bytes)
+				}
+			}
+			count++
+		}
+	}
+	unsafe {
+		free(tmp_value)
+		free(tmp_key)
+		d.deletes = 0
+		// TODO: reallocate instead as more deletes are likely
+		free(d.all_deleted)
+	}
+	d.len = count
+	old_cap := d.cap
+	d.cap = if count < 8 { 8 } else { count }
+	unsafe {
+		d.values = realloc_data(d.values, d.value_bytes * old_cap, d.value_bytes * d.cap)
+		d.keys = realloc_data(d.keys, d.key_bytes * old_cap, d.key_bytes * d.cap)
+	}
+}